There is plenty of evidence that Capt. Smith was not reactive despite some impressions that Lightoller or Boxhall may have given. Two examples,
QM Hichens: I heard the Captain say "Get all the boats out and serve out the belts." That was after 12.
AB Poingdestre: I was going up on to the boat deck to go towards my own boat, and I heard the Captain pass the remark, "Start putting the women and children in the boats," and then I went to my boat, No. 12.
One has to also keep in mind the noise of the escaping steam that was going on for quite some time, and some orders may not have been heard by everyone.